U-Line Ice Maker Amb Thrm Short: Ambient Sensor Shorted

Amb Thrm Short at a glance

Code

Amb Thrm Short

Appliance

U-Line ice machine

Applies to

U-Line ice makers with an ambient air thermistor

Type

Needs attention soon

Can you clear it yourself?

Sometimes, after the safe checks below

Most likely cause

A pinched or damaged wire on the ambient thermistor

What you may notice with Amb Thrm Short

• The display shows Amb Thrm Short
• The unit makes less ice or none at all
• Damp conditions are present near the cabinet
• The code returns shortly after restarting

How the ice machine detects Amb Thrm Short

Air temperature around the unit is read by the ambient thermistor, so the control knows how warm the surroundings are. A thermistor works by changing its resistance as the temperature changes, and the board converts that change into a reading it compares with its internal sensors.

When the circuit is shorted, the resistance collapses and the board sees a value no real room would produce. The control cannot treat it as air temperature, and it reports Amb Thrm Short. Without a trustworthy room reading, the unit cannot judge how much heat it must shed, so it may adjust how it makes ice or stop until the sensor circuit is sound again.

Likely causes of Amb Thrm Short

• A pinched or damaged wire on the ambient thermistor
• An ambient thermistor sensor that has failed
• Moisture on the ambient sensor connector

Can you keep using the ice machine with Amb Thrm Short?

You can leave the unit in place for the short term, though it may not make ice well. Because moisture can be involved, do not keep running it if you see water around electrical parts or smell something hot. Switch it off at the breaker and wait for a technician.

What you can safely check

1. Switch the ice maker off, unplug it or turn off the breaker, and give it a moment to settle.
2. Restore power after about a minute.
3. Check the space around the unit for splashes, leaks or heavy humidity, and wipe the outside dry.
4. Watch whether Amb Thrm Short comes back.
5. If it does, call us and mention where the unit is installed.

What our technician does for Amb Thrm Short

• Look at the ambient thermistor wire for pinches or worn insulation
• Check the connector for moisture or corrosion
• Test the ambient sensor and replace it if it reads wrongly

How to keep Amb Thrm Short from coming back

• Keep spills and splashing water away from the unit and its rear panel
• Avoid crushing the wiring when sliding the unit in or out
• For units outdoors, keep covers and drainage in good order against rain and salt air
• Wipe condensation from the cabinet during damp summer weeks

Technical reference

Code

Amb Thrm Short

Appliance

U-Line ice machine

Control family

U-Line ice makers with an ambient air thermistor

Maker documentation

U-Line owner manuals and support

Checked

November 2026

Code meanings come from the maker’s documentation and our own repair work; we do not reprint the maker’s document. Confirm the full model number before acting on a code. We are an independent repair company, not affiliated with U-Line Corporation.